Both hybrid-bootonly-20180323-00.iso and hybrid-bootonly.iso fail to boot to userland on coreboot 4.14 + SeaBIOS 1.14, and about 50 seconds into booting panic at stand/libsa/zalloc_malloc.c:131
Crash details shown on screen are:
"panic: free: guard1 fail @ 0x5ceb7fe0 from unknown:0
--> Press a key on the console to reboot <--"